fixed bug where CATE is not returned by lr

Signed-off-by: Amit Sharma <amit_sharma@live.com>

dowhy/causal_estimators/regression_estimator.py

@@ -117,6 +117,8 @@ def estimate_effect(
         self._target_units = target_units
         self._treatment_value = treatment_value
         self._control_value = control_value
+        if need_conditional_estimates is None:
+            need_conditional_estimates = self.need_conditional_estimates 
         # TODO make treatment_value and control value also as local parameters
         # All treatments are set to the same constant value
         effect_estimate = self._do(data, treatment_value) - self._do(data, control_value)